In order to facilitate the driving of a motor vehicle and to make it safer, it is desirable to provide the driver with information (for example the maximum speed permitted on the road) and to warn them of problems (for example when the vehicle deviates from its driving line).
In order to generate this information and these warnings, a known solution is to use sensors designed to detect and to interpret the infrastructures of the road (road signs, position of the continuous and broken lines, etc.).
The reliability of this information and these warnings depends, to a large extent, on the quality of the detection of the infrastructures of the road. Unfortunately, this detection is affected by two problems.
The first problem is that the infrastructures degrade over time, for example owing to the weather conditions, to their exposure to the sun, and to the number of cars driving over them. It therefore turns out to be necessary to monitor their state in order to replace them before they are no longer readable.
Currently, this monitoring job is carried out by physical persons, who are employed to drive along roads and to fill in a database in which each infrastructure is denoted according to its readability and hence to its need, or otherwise, for repair/replacement.
The second problem is that it can happen that the sensors exhibit malfunctions.
Although it is rather easy to detect a complete failure of a sensor, it remains more difficult to detect a problem affecting this sensor that does not cause its complete shutdown. Such a problem may however be detrimental to the quality of the detection of the infrastructures of the road.
By way of example, a displacement of the sensor with respect to its support may affect the quality of the detection of the infrastructures of the road without this however being easily detectable. Dirt stuck to the lens of a sensor can also affect the quality of the detection.